1. Field of the Invention
Embodiments of the present invention generally relate to therapeutic mechanisms for treating brain disorders, and more particularly, to a method and apparatus for removing harmful organic anions and proteins from a mammalian's ventricular cerebrospinal fluid in the treatment of brain disorders.
2. Description of the Related Art
In advanced aging and with brain disorders such as Alzheimer's Disease, there are many degenerative changes in the cranial compartment, particularly in the choroid plexus. The choroid plexus is the area of the brain that is responsible for the production of cerebrospinal fluid (CSF). Some of the degenerative changes have adverse effects on the normal removal of organic anions and proteins from ventricular cerebrospinal fluid (“Volume Transmission of CSF: Complications in Aging and AD, Johansson et. al., Brown Medical School, CSF Research 2004). Cerebrospinal fluid is a clear bodily fluid that maintains, cradles, cushions and bathes the central nervous system. Cerebrospinal fluid occupies the spine's sub-arachnoid space and the ventricular system around and inside the brain.
In addition, the CSF system maintains a delicate balance between production and absorption of cerebrospinal fluid. This is especially true as the brain loses its elasticity in the aging process. Some clinicians have reported that there is a relationship between Alzheimer's disease (AD) and Normal Pressure Hydrocephalus (NPH). Thus, accessing the CSF system in the cranial or spinal subarachnoid space to administer therapeutic treatment for brain disorders may disturb the system's delicate balance leading to complications (e.g., CSF leak or NPH). Such complications may necessitate some level of temporary or permanent CSF diversion. Further, experts such as Michael Williams, MD of John Hopkins University have suggested that patients experiencing symptoms of AD and NPH may not have one or the other, but instead have a certain degree of both diseases.
However, such access of the CSF system may be necessary because of the Blood-Brain-Barrier. The Blood-Brain-Barrier is the body's natural central nervous system defense mechanism. The Blood-Brain-Barrier is very effective in restricting the movement of certain molecules to the brain. Therefore, infections of the brain are quite rare. Ironically, the same effective protection makes the treatment of brain infections or diseases that do occur very difficult. That is, the Blood-Brain-Barrier prevents therapeutic drugs that may be introduced into the blood stream or taken orally from reaching the brain in the same manner in which harmful substances or infections are prevented from reaching the brain.
Accordingly, there exists a need for a method of removing harmful organic anions and proteins from a mammalian's ventricular cerebrospinal fluid without upsetting the delicate balance of cerebrospinal fluid production and absorption in the CSF system.